All of the following have been associated with disease,but ________ is a vector that introduces the actual pathogen rather than being a pathogen itself and does NOT cause any illness directly.
A) a bacterium
B) the flea
C) a protist
D) a virus

Question

Quizplus · Accepted Answer

The flea is a vector that can transmit disease by introducing the actual pathogen (such as Yersinia pestis) into the host's bloodstream, but it does not cause illness directly. Bacteria, protists, and viruses can all be pathogens that cause disease.

All of the Following Have Been Associated with Disease,but ________